U.S. patent application number 13/018939 was filed with the patent office on 2011-05-26 for method of making a molded article.
This patent application is currently assigned to SABIC INNOVATIVE PLASTICS IP B.V.. Invention is credited to Sapna Blackburn, Kwan Hongladarom, Mike M. Laurin, Jan Pleun Lens, Hendrik Theoderus van de Grampel.
Application Number | 20110123764 13/018939 |
Document ID | / |
Family ID | 39580452 |
Filed Date | 2011-05-26 |
United States Patent
Application |
20110123764 |
Kind Code |
A1 |
Blackburn; Sapna ; et
al. |
May 26, 2011 |
METHOD OF MAKING A MOLDED ARTICLE
Abstract
In various embodiments, a method of making a molded article
comprises forming a composite into a desired shape for the article,
and cutting the formed article to form desired openings in the
article. The composite comprises a top layer that comprises a blend
of a first polycarbonate comprising repeat units of dimethyl
bisphenol cyclohexane and a second polycarbonate comprising repeat
units of bisphenol A, said second polycarbonate being different
from said first polycarbonate, wherein the repeat units of dimethyl
bisphenol cyclohexane are present in an amount of at least 50
weight percent relative of the total repeat units in the top layer,
and (b) a second layer comprising a bisphenol-A polycarbonate, said
second layer being joined with the top layer.
Inventors: |
Blackburn; Sapna; (Mt.
Vernon, IN) ; Hongladarom; Kwan; (Mt. Vernon, IN)
; Laurin; Mike M.; (Pittsfield, MA) ; Lens; Jan
Pleun; (Breda, NL) ; van de Grampel; Hendrik
Theoderus; (Bergen op Zoom, NL) |
Assignee: |
SABIC INNOVATIVE PLASTICS IP
B.V.
Bergen op Zoom
NL
|
Family ID: |
39580452 |
Appl. No.: |
13/018939 |
Filed: |
February 1, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11734994 |
Apr 13, 2007 |
|
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13018939 |
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Current U.S.
Class: |
428/137 ;
264/154 |
Current CPC
Class: |
Y10T 428/31507 20150401;
C08L 69/00 20130101; C08L 69/00 20130101; C08L 2666/18 20130101;
Y10T 428/24322 20150115; B32B 27/36 20130101 |
Class at
Publication: |
428/137 ;
264/154 |
International
Class: |
B32B 3/10 20060101
B32B003/10; B29C 47/06 20060101 B29C047/06 |
Claims
1. A method of making a molded article comprising: forming a
composite into a desired shape for the article, and cutting the
formed article to form desired openings in the article, wherein the
composite comprises: (a) a top layer comprising a blend of a first
polycarbonate comprising repeat units of dimethyl bisphenol
cyclohexane; and a second polycarbonate comprising repeat units of
bisphenol A, said second polycarbonate being different from said
first polycarbonate, wherein the repeat units of dimethyl bisphenol
cyclohexane are present in an amount of at least 50 weight percent
relative of the total repeat units in the top layer; (b) a second
layer comprising a bisphenol-A polycarbonate, said second layer
being joined with the top layer.
2. The method of claim 1, wherein the repeat units of dimethyl
bisphenol cyclohexane are present in an amount of from 60 to 75
weight percent relative of the total repeat units in the top
layer.
3. The method of claim 2, wherein the first polycarbonate is
dimethyl bisphenol cyclohexane homopolymer.
4. The method of claim 3, wherein the repeat units of dimethyl
bisphenol cyclohexane are present in an amount of from 60 to 75
weight percent relative of the total repeat units in the top
layer.
5. The method of claim 1, wherein the second polycarbonate is a
bisphenol-A homopolymer.
6. The method of claim 1, further comprising the step of molding
behind the formed article after cutting with a resin to form a
molded article.
7. A molded article prepared by the method of claim 6.
8. A method of making a molded article, comprising: forming a
composite into a desired shape for the article, and cutting the
formed article to form desired openings in the article, wherein the
composite comprises: (a) a top layer comprising a blend of a first
polycarbonate comprising repeat units of dimethyl bisphenol
cyclohexane, wherein the repeat units of dimethyl bisphenol
cyclohexane are present in an amount of from 60 to 75 weight
percent relative of the total repeat units in the top layer; and a
second polycarbonate comprising repeat units of bisphenol A, said
second polycarbonate being different from said first polycarbonate,
wherein the repeat units of dimethyl bisphenol cyclohexane are
present in an amount of at least 50 weight percent relative of the
total repeat units in the top layer; (b) a second layer comprising
a bisphenol-A polycarbonate, said second layer being joined with
the top layer.
9. The method of claim 8, wherein the first polycarbonate is
dimethyl bisphenol cyclohexane homopolymer.
10. The method of claim 9, wherein the repeat units of dimethyl
bisphenol cyclohexane are present in an amount of from 60 to 75
weight percent relative of the total repeat units in the top
layer.
11. The method of claim 8, wherein the second polycarbonate is a
bisphenol-A homopolymer.
12. The method of claim 8, further comprising the step of molding
behind the formed article after cutting with a resin to form a
molded article.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent
application Ser. No. 11/734,994, filed Apr. 13, 2007, which is
incorporated by reference herein in its entirety.
BACKGROUND
[0002] There is a need for thermoformable plastic films with good
mechanical properties, good surface finish, high transparency, film
processability and scratch resistance for in-mold decorating (IMD)
applications for electronic components, cell phones, computer
laptops and automotive bezels, etc. Film processability refers to
film ability to be thermoformed into three-dimensional shape and
then die-cut in specific locations to achieve a specific shape from
the film without forming cracks. Film made from BPA-based
polycarbonate resin is able meet these application requirements.
However, this PC film is very easy to scratch.
[0003] One-way to achieve better resistance to scratching is to
post-coat the three-dimensional thermoformed polycarbonate
components with hard coat materials. This method adds extra
post-production coating step and cost to the entire process.
Another method is to pre-coat polycarbonate film with hard coat
materials; the coating process is efficient since it is carried out
before thermoforming on flat film. However, hard coat materials
once cured are brittle and cannot be thermoformed or die cut
effectively. Another route is to pre-coat polycarbonate film with
hard coat materials but leave the coating uncured. This allows the
film to be thermoformable and die-cut able. The drawback of this
method is the extra steps involved in prevention of pre-mature
curing of light sensitive uncured coating and handling
vulnerability of the soft and easily damaged uncured coated film.
Special packaging and outfitting the film processing area with
special lights is used to prevent pre-mature curing.
[0004] This application relates to a scratch-resistant composite
material, and to articles made using such a material. In the
layered composites and articles of the invention, the outer layer
is a polycarbonate comprising a blend of a dimethyl bisphenol
cyclohexane polycarbonate (DMBPC-PC) and a bisphenol A
polycarbonate (BPA-PC).
[0005] DMBPC is a dihydroxy monomer having the formula:
##STR00001##
[0006] Polymerization of this monomer into a polycarbonate is known
in the art, for example from U.S. Patent Publication No.
2007/0009741 published Jan. 11, 2007 which is incorporated herein
by reference in its entirety. In this publication, the use of
DMBPC/BPA copolymers as scratch resistant coatings for
polycarbonate articles is disclosed.
SUMMARY
[0007] Disclosed, in various embodiments, are methods of making a
molded article.
[0008] In one embodiment, a method of making a molded article
comprises forming a composite into a desired shape for the article,
and cutting the formed article to form desired openings in the
article. The composite comprises: (a) a top layer comprising a
blend of a first polycarbonate comprising repeat units of dimethyl
bisphenol cyclohexane; and a second polycarbonate comprising repeat
units of bisphenol A, said second polycarbonate being different
from said first polycarbonate, wherein the repeat units of dimethyl
bisphenol cyclohexane are present in an amount of at least 50
weight percent relative of the total repeat units in the top layer;
(b) a second layer comprising a bisphenol-A polycarbonate, said
second layer being joined with the top layer.
[0009] In another embodiment, a method of making a molded article
comprises forming a composite into a desired shape for the article,
and cutting the formed article to form desired openings in the
article. The composite comprises (a) a top layer comprising a blend
of a first polycarbonate comprising repeat units of dimethyl
bisphenol cyclohexane, wherein the repeat units of dimethyl
bisphenol cyclohexane are present in an amount of from 60 to 75
weight percent relative of the total repeat units in the top layer;
and a second polycarbonate comprising repeat units of bisphenol A,
said second polycarbonate being different from said first
polycarbonate, wherein the repeat units of dimethyl bisphenol
cyclohexane are present in an amount of at least 50 weight percent
relative of the total repeat units in the top layer, and (b) a
second layer comprising a bisphenol-A polycarbonate, said second
layer being joined with the top layer.
[0010] These and other non-limiting characteristics are more
particularly described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The FIGURE shows a schematic of a calendaring co-extrusion
process.
DETAILED DESCRIPTION
Definitions
[0012] In the specification and the claims which follow, reference
will be made to a number of terms which shall be defined to have
the following meanings:
[0013] The singular forms "a", "an" and "the" include plural
referents unless the context clearly dictates otherwise.
[0014] "Optional" or "optionally" means that the subsequently
described event or circumstance may or may not occur, and that the
description includes instances where the event occurs and instances
where it does not.
[0015] "Polycarbonate", unless described otherwise, refers to
polycarbonates incorporating repeat units derived from at least one
dihydroxy aromatic compound and includes copolyestercarbonates, for
example a polycarbonate comprising repeat units derived from
resorcinol, bisphenol A, and dodecandioic acid. Nothing in the
description and claims of this application should be taken as
limiting the polycarbonate to only one kind of dihydroxy repeat
unit unless the context is expressly limiting. Thus, the
application encompasses copolycarbonates with repeat units of 2, 3,
4, or more types of different dihydroxy compounds.
[0016] "Repeat unit(s)" means the units that are contained within
the polymer chain of the polycarbonate and are derived from the
starting dihydroxy compositions described below. The articles of
the present invention may be transparent, translucent, or opaque
depending on the application.
[0017] "Transparent" is understood to mean that the sheet or
article has light transmission of 50%, preferably 70%, and most
preferably greater than 80% and a haze of less than 7, preferably
less than 5, more preferably less than 2. Further, the term
"transparent" does not require that all of the sheet or article is
transparent and portions of the sheet or article may be opaque or
translucent, for example to form a decorative pattern. All light
transmission and haze values referred to herein are measured by
ASTM D1003 at a thickness of 4.0 millimeters.
[0018] "Translucent" is herein defined as having a light
transmission of about 25 to about 95% and haze less than 104% and
greater than 7%.
[0019] "Coating" is a substance placed on the inner and/or outer
surfaces of the sheet or an article of the present invention.
Typical coatings are anti-static coatings, UV protection coating,
Easy Clean (R) coatings, anti-microbial coatings, infrared
shielding coatings, and hard coats. Typical hard coats can be
silicone hard coats, acrylate hard coats (UV or thermally curable),
silicone hard coats with acrylate primers, polyurethane hard coats,
and melamine hard coats. Silicone hard coats are often
preferred.
[0020] "Coplanar" as used in the present invention is not meant to
indicate that the articles of present invention are necessarily
flat or defined solely in single plane. The term as used herein
means that the identified "coplanar" layer has the same relative
shape as the underlying or overlying layer that it is referenced
to. For example, the articles of the present invention may be
curved.
Composites of the Invention
[0021] The invention provides molded articles formed from the
composite of the invention. In these applications, the composite
provides the surface scratch resistance of the DMBPC-PC plus the
impact resistant normally associated with polycarbonates. Specific
articles include cell phone covers, cell phone lens, computer cases
and covers, particularly for laptops, and automotive bezels.
[0022] The present invention provides composites that comprise at
least two polymeric layers, referred to herein as a top layer and a
second layer. Additional polymeric layers may also be present
without departing from the invention. However, as the term "top
layer" implies, this layer is the outermost layer on one surface of
the composite during molding, although it may be covered with a
coating after molding of the composite into an article.
[0023] The multi-layer composite of the invention is suitably
formed using a continuous calendaring co-extrusion process as shown
schematically in the FIGURE. In this process, extruders 1 and 2
supply the molten resin for the individual layers (i.e. the top
layer, the second layer and any additional polymeric layers) into a
feed block 3. A die 4 forms a molten polymeric web that is feed to
a set of calendaring rolls 5. Typically, there are 2 to 4
counter-rotating cylindrical rolls made from steel or rubber-coated
steel. The rolls may be heated or cooled. The molten web formed by
the die is successively squeezed between these rolls. The
inter-roll clearances or "nips" through which the web is drawn
determines the thickness of the layers. The multi-layer composite
of the invention may also be formed from separate pre-formed films
corresponding to the polymeric layers which are subsequently
laminated together, for example using heated rolls and optionally
adhesive tie layers.
[0024] The thickness of the composite of the invention is
determined by the application and the equipment used in forming the
composite. For many applications, the thickness of the material
will range from 0.001 inches to 0.5 inches (25 micrometers to 12.7
mm), for example 0.002 to 0.030 inches (50 to 750 micrometers).
Overall thickness of 0.007 to 0.30 inches (175 micrometers to 7.62
mm) are preferred for some applications.
[0025] The top layer in the composites of the invention comprises a
blend of a first polycarbonate comprising repeat units of dimethyl
bisphenol cyclohexane; and a second polycarbonate comprising repeat
units of bisphenol A. The second polycarbonate is different from
said first polycarbonate. In the top layer, the repeat units of
dimethyl bisphenol cyclohexane are present in an amount of at least
50 weight percent relative of the total repeat units in the top
layer, preferably in a weight ratio of from 60 to 75 weight
percent.
[0026] This composition of the top layer is different from the
copolymer layers which are described in the examples of U.S. Patent
Publication No. 2007/0009741. As will be understood in the art,
random copolymers tend to adopt one set of properties which is
somewhere between the properties of homopolymers of the individual
polymers. In blends on the other hand, each polymer type retains
its own original properties and these interact in different ways to
form the final properties of the blend. Furthermore, blends may
encounter issues with miscibility and compatibility of the polymers
that is not an issue in a homogenous copolymer.
[0027] In U.S. 2007/0009741, results are provided for
DMBPC-PC/BPA-PC blends and for a top layer of a DMBPC-PC
homopolymer, formulated with a UV stabilizer. The scratch
resistance of these materials was found to be good. However, it was
subsequently determined that particularly in the case of the
homopolymer top layer, the impact strength and the ability to form
and trim molded articles from this material was poor. The present
invention in which blends are used in the top layers addresses this
issue, while generally maintaining the same level of performance as
the copolymer in other relevant respects such as scratch
resistance.
[0028] In one specific embodiment of the invention, the first
polycarbonate in the top layer is a DMBPC homopolymer. Suitable
DMBPC homopolymers have molecular weights in the range of 18,000 to
35,000, preferably 20,000 to 30,000 and more preferably from 20,000
to 25,000 as determined by GPC with PC standards. The polymers have
Tg values in the range of 135 to 145.degree. C., that are
comparable to that of BPA homopolymer, and therefore that can be
easily used in the coextrusion process.
[0029] In another specific embodiment, the second polycarbonate in
the top layer is a BPA homopolymer. Suitable BPA homopolymers have
molecular weights in the range of 20,000 to 35,000, preferably
21,000 to 31,000 and more preferably from 25,000 to 3 1,000
(polycarbonate standards).
[0030] In yet a further specific embodiment, the first
polycarbonate in the top layer is DMBPC homopolymer and the second
polycarbonate in the top layer is BPA homopolymer, each as
described above.
[0031] The top layer has sufficient thickness to provide the level
of scratch resistance required for the application. The top layer
may be from 10% to 99% of the total thickness of the composite, for
example 10 to 50%, more preferably 20 to 40% and most preferably 20
to 35%. Thus, the top layer may be from 0.0001 to nearly 0.5 inches
thick (2.5 micrometers to 12.7 mm), but will more commonly be in
the range of from 0.0007 to 0.029 inches (1.78 micrometers to 0.74
mm). Increasing the thickness of the cap layer as a % of the total
thickness has an affect on the measured pencil hardness. For
example, for a cap layer with 50% DMBPC, the pencil hardness (1000
g) of a 10 mil (0.254 mm) total thickness film varies as follows:
10%-F, 20%-F; 30%-H, 50%-H. For higher levels of DMBPC in the cap
layer, the hardness achieved at greater thickness could be higher,
for example 2 H or 3 H.
[0032] The second layer of the invention is a polymer layer
comprising repeat units of bisphenol A. This layer may be
transparent, translucent or opaque, depending on the application,
and may contain metal flakes, fillers, colorant and the like to
impart a desired visual appearance to articles made from the
composite.
[0033] In some embodiments of the invention, the second layer is a
BPA homopolymer, which may the same as or different from any
BPA-homopolymer used in forming the blend for the top layer). In
another specific embodiment, the second polycarbonate is a BPA
homopolymer. Suitable BPA homopolymers have molecular weights in
the ranges set forth above for the materials in the top layer. The
polymer of the second layer may be copolymer or a blend with
additional repeat units selected to achieve properties suited for a
given application.
[0034] In some embodiments, as reflected below in the examples, the
composite of the invention may consist of just the top layer and
the second layer. In other cases, additional layers may be
included. Such additional layers can be divided into two groups:
additional layers between the top layer and the second layer, and
additional layers on the side of the second layer opposite the top
layer.
[0035] If there are no additional layers between the top layer and
the second layer, the two layers are referred to herein as being
joined and directly adjacent. If there is an additional layer
between the top layer and the second layer, the two layers are
still joined (via the additional layer(s)), but they are no longer
directly adjacent. Additional layers used between the top layer and
the second layer may serve as tie layers (should compatiblization
be necessary between the top layer and the second layer) or may be
used to create decorative effects.
[0036] Additional layers disposed on the side of the second layer
opposite the top layer may be of any type desirable based on the
intended application of the composite. They may include
fiber-reinforced substrates, decorative layers such as inks,
metallization or hot stamping, or tie layers to aid in
compatibility with a molded, extruded, laminated or otherwise
bonded layer. In one specific embodiment, an additional layer in
this position has the same composition as the top layer, to provide
scratch resistance on both surfaces of a molded article.
Method of the Invention
[0037] The present invention also provides a method of making a
molded article comprising the steps of forming a composite in
accordance with the invention into a desired shape for the article,
and cutting the formed article to form desired openings in the
article. This formed article suitably serves as an insert in a
mold, which is then molded behind with resin in a conventional
manner to form a final molded article.
[0038] In the method of the invention, the step of forming the
composite into a desired shape may be done using any forming
processes including without limitation thermoforming, pressure
forming, pressure assist thermoforming, hydro forming, embossing,
match die forming, zero gravity forming, plug assist forming, and
snap back forming.
[0039] In the method of the invention, the step of cutting the
formed article can be done by any suitable cutting technique for
the thickness of the material, including without limitation
stamping, die cutting, match die cutting, steel rule die cutting,
laser cutting, routering, and water jet cutting.
[0040] In the method of the invention, the step of molding behind
can be done using any conventional molding technique, including
without limitation injection molding, foam molding, gas assist
injection molding, blow molding, injection compression molding, and
compression molding. Suitable process and materials are known, for
example from U.S. Pat. Nos. 6,458,913, 6,465,102 and 6,548,005
which are incorporated herein by reference.
[0041] As is apparent from the discussion of the composites above,
decorative features in the molded articles may be incorporated into
the composite prior to forming. They may also be added during the
molding behind step, or after molding. The article may also be
hard-coated with a top coat after the molding behind step.
[0042] The invention will now be further described with reference
to the following non-limiting examples.
EXAMPLES A-E
[0043] Co-extruded film articles comprising of a top layer
containing various amounts of DMBPC-PC and bisphenol A
polycarbonate substrate were made using the calendering process.
Commercial grade Lexan.RTM. ML9735 was used for the substrate. The
DMBPC-PC used in the compositions was made by a melt process and
had the following properties; [0044] MW 25,000 (PC standards)
[0045] MFR 8 g/10 min [0046] Tg 137.degree. C.
[0047] The BPA-PC used was LEXAN.RTM. 101 which has the following
properties: [0048] MW 30,500 (PC standards) [0049] MFR 7 g/10 min
[0050] Tg 144.degree. C.
[0051] The two layer composite formed had an overall thickness of
about 10 mil (250 micrometers), of which the top layer was about
20% i.e. about 2 mil (50 micrometers).
[0052] The film samples were tested for scratch resistance via
pencil hardness lest (ASTM D3363), abrasion resistance via tabor
abrasion test at 50 cycle(ASTM D1044) and impact performance via
multi-axial impact test (ASTM D3763). The sides with DMBPC-PC
containing cap layers were the sides impacted. The film samples
were also thermoformed using a cellular phone cover male forming
tool. The thermoformed films were then trimmed to desired geometry
on a matched die-trimming tool. Visual evaluations were made on the
thermoformed and die-cut parts; judging for part definition,
appearance and occurrences of surface defects such as wrinkles from
thermoforming and surface cracks from trimming process.
[0053] The formulations tested and the results from the tests are
tabulated in Table 1.
TABLE-US-00001 TABLE 1 Examples A B C D E Description PC Film DMBPC
cap DMBPC cap DMBPC cap DMBPC cap PC Film PC Film PC Film PC Film
Wt % DMBPC-PC in 0% 50% 62% 73% 85% Cap Layer Substrate Layer Lexan
.RTM. ML9735 Lexan .RTM. ML9735 Lexan .RTM. ML9735 Lexan .RTM.
ML9735 Lexan .RTM. ML9735 Pencil Hardness 6B F H 2H 3H Tabor
Abrasion (del 24.8 20.7 19.0 18.5 15.7 haze/50 cycles) Multi-axial
Impact 4.9 4.2 4.5 2.50 0.30 (Total Energy J) Forming Capability
Good* Good* Good* Good* Good* Trimming Capability Good* Good* Good*
Good* Poor* * *Good (good definition and no cracks during forming,
no cracks during trimming) *Poor (cracks along line of impact from
match die tool)
[0054] Table 1 shows increasing pencil hardness as percentage of
DMBPC-PC in the cap layer increases. It will be appreciated that
pencil hardness is a measurement that is subject to variations
dependent on the test taker, and that these results should be
considered as comparative, within this data set but not necessarily
as absolute. Even at 50 wt. % DMBPC-PC (Example B) the pencil
hardness of F is substantially higher than those tested for
polycarbonate film at 6B (Example A). At 85 wt. % DMBPC-PC (Example
E) the hardness is rated at an excellent 3 H.
[0055] The examples also showed similar abrasion resistance
improvement with increasing DMBPC content. At 50% DMBPC content
(Example B) abrasion resistance as measured by delta haze after
exposure to tabor wheel for 50 cycles showed 16.5% improvement over
Example A. At 62 wt % DMBPC-PC content (Example C) the improvement
is 23.4% and at 85 wt % DMBPC-PC (Example E) the improvement is
36.7% over polycarbonate. The impact performance is observed to
decrease with the increasing DMBPC-PC content. The largest impact
drop is observed at 85 wt % DMBPC-PC (Example E) which only retains
5.9% of the impact of Example A, a 100% polycarbonate film. The
smallest impact drop is observed for 62 wt % DMBPC-PC (Example C)
which retained 91.8% of the impact performance of Example A. At 50
wt % DMBPC-PC (Example B) the impact retention is observed to be
79.6%.
[0056] The forming capabilities are judged to be good for all
DMBPC-PC contents evaluated, however at 85 wt % DMBPC-PC content
(Example E), the ability to trim the part using match die tool is
unacceptable with cracks observed along the impact lines when the
parts are punched out of the die tool.
[0057] It is thus observed that by using DMBPC-PC/BPA-PC blend for
the top layer on a polycarbonate co-extruded calendered films
substantial improvement of scratch and abrasion resistance can be
obtained. By keeping the DMBPC-PC level below that of 85 wt % and
preferably from 50 wt % to 75 wt %; we are able to produce
co-extruded films that can be thermoformed and trimmed. Some impact
drops are observed with introduction of DMBPC-PC into the cap
layer, with the amount of 62 wt % DMBPC-PC content (Example C)
showing the least reduction at 8.2% impact drop from all
polycarbonate film (Example A).
[0058] All ranges disclosed herein are inclusive of the endpoints,
and the endpoints are independently combinable with each other
(e.g., ranges of "up to 25 wt. %, or, more specifically, 5 wt. % to
20 wt. %", is inclusive of the endpoints and all intermediate
values of the ranges of "5 wt. % to 25 wt. %," etc.). "Combination"
is inclusive of blends, mixtures, alloys, reaction products, and
the like. Furthermore, the terms "first," "second," and the like,
herein do not denote any order, quantity, or importance, but rather
are used to denote one element from another. The terms "a" and "an"
and "the" herein do not denote a limitation of quantity, and are to
be construed to cover both the singular and the plural, unless
otherwise indicated herein or clearly contradicted by context. The
suffix "(s)" as used herein is intended to include both the
singular and the plural of the term that it modifies, thereby
including one or more of that term (e.g., the film(s) includes one
or more films). Reference throughout the specification to "one
embodiment", "another embodiment", "an embodiment", and so forth,
means that a particular element (e.g., feature, structure, and/or
characteristic) described in connection with the embodiment is
included in at least one embodiment described herein, and may or
may not be present in other embodiments. In addition, it is to be
understood that the described elements may be combined in any
suitable manner in the various embodiments.
[0059] While particular embodiments have been described,
alternatives, modifications, variations, improvements, and
substantial equivalents that are or may be presently unforeseen may
arise to applicants or others skilled in the art. Accordingly, the
appended claims as filed and as they may be amended are intended to
embrace all such alternatives, modifications variations,
improvements, and substantial equivalents.
* * * * *